<?php

/**

 *  @author：jiangzaixing 20160314

 *  获取静态文件方法

 */

class StaticFile

{

    const  MAP_FILE_NAME = 'map.json';

    static public $files = null;

    static public $fileMap = null; //静态文件地址对应map

    //要操作的目录

    static public $pathList = array(

        'image/',

        'css/',

        'js/'

    );

    //需要压缩的文件

    static public $extList = array(

        'js','css','gif','jpg','png'

    );

    static public $toPath = 'scripts/temp/';

    /**

     * 获取最新的静态文件

     * @param string $fName 文件名称

     */

    static public function getFile( $fName ){

        $from = dirname(__FILE__).'/../../scripts/' ;

        $to = dirname(__FILE__).'/../../scripts/temp/';

        if( !self::$fileMap )

            self::$fileMap = json_decode( file_get_contents( $to.self::MAP_FILE_NAME ) ,true );

        return  self::$fileMap[md5($fName)];

    }

    /**

     * 批量生成新的静态文件

     */

   static public function genFiles(){

        $from = dirname(__FILE__).'/../../scripts/' ;

        $to = dirname(__FILE__).'/../../scripts/temp/' ;

        foreach( self::$pathList as $path ){

            self::scanfDir( $from.$path );

        }

        foreach ( self::$files as $file ){

           self::genFile( $file , $from , $to);

        }

        $sMap = file_put_contents( $to.self::MAP_FILE_NAME, json_encode( self::$fileMap ) ); 

   }

   static public function scanfDir( $dir , $level = 0 ){

        if(( $level == 0 &&!is_dir($dir)) || !is_readable($dir)){

            return array( 'isOk'=>false , 'msg'=>"$dir 路径无效" );

        }

        $handler =  opendir($dir);

        while( false !== ($file = readdir($handler)) ){

            if(in_array($file,array('.','..'))) continue;

            if(is_dir( $dir.$file )){

                self::scanfDir( $dir.$file."/", $lev = $level+1 );

                continue;

            }

            self::$files[] = $dir.$file;

        }

        closedir($handler);

    }

    /**

     *  创建多级目录

     */

    static public function createDir( $path ){

        if (file_exists($path))

            return true;

        self::createDir(dirname($path));

        mkdir($path, 0777);

    }

    /**

     * 替换css中图片地址  只能写死了。

     */

    static public function replaceCssImg( $content , $from , $to ){

         $ret = preg_replace_callback('/url\(\/scripts\/([\s\S]*?)\)/',function( $m ){

            $_idx = md5( $m[1] );

            return '/scripts/temp/'.self::$fileMap[$_idx];

        }, $content);

        unset( $content );

        return $ret;

    }

    /**

     * 生成对应文件

     */

    static public function genFile( $file, $from ,$to ){

        $len = strlen( $from );

        //获取文件在目录中的目录结构 创建文件夹

        $info = pathinfo($file);

        $relUrl = substr( $file, $len );

        $_path = dirname( $relUrl );

        self::createDir( $to.$_path );

        //获取静态文件内容

        $_fcontent = file_get_contents($file);

        if( $info['extension'] == 'css' )

            $_fcontent = self::replaceCssImg( $_fcontent , $from , $to );

        if( in_array( $info['extension'] , self::$extList ) ){

            //生成静态文件MD5值

            $_idx = md5_file( $file );

            $newName = sprintf( '%s.%s.%s', $info['filename'], $_idx, $info['extension']);

            file_put_contents( $to.$_path.'/'.$newName, $_fcontent);

            self::$fileMap[md5($relUrl)] = $_path.'/'.$newName;

        }

        // 保存文件内容到新文件

        $_oname = sprintf( '%s/%s.%s', $to.$_path, $info['filename'], $info['extension'] );

        $ret = file_put_contents( $_oname, $_fcontent);

        unset( $_fcontent );

        return $ret;

    }

}